• Journal of the Korean Institute of Gas
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• v.20 no.5
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• pp.104-111
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• 2016

Recently, the quantities of chemical material are increasing in chemical industries. At that time, release accident is increasing due to aging of equipment, mechanical failure, human error, etc. and industrial complexes found community properties in a specific area. For that matter, chemical release accident can lead to hight probability of large disaster. There is a need to analyze the boundaries optimal sensor placement calculated by selecting release scenarios through release condition and wether condition in a chemical process for release detection and response. This paper is to investigate chlorine release accident scenarios using COMSOL. Through accident scenarios, a numerical calculation is studied to determine optimized sensor placement with weight of detection probability, detection time and concentration. In addition, validity of sensor placement is improved by robustness analysis about unpredicted accident scenarios. Therefore, this verifies our studies can be effectively applicable on any process. As mention above, the result of this study can help to place mobile sensor, to track gas release based concentration data.

• Conservation Science in Museum
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• v.8
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• pp.81-95
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• 2007

The Conservation Science Team of National Museum of Korea has established the data base of lead isotope ratio as the scientific research of bronze patina, which was acquired from conservation process of metal objects, and based on this result, it intends to conduct the research related to the production places of raw material for the bronze objects. As the equipment for analysis of lead isotope ratio of the bronze patina, the thermal ionization mass spectrometer (TIMS) was used. As part of the research, in 2007, the 11 samples of the bronze Patina from the objects, believed to belong to of Nangnang(Lelang), the 6 items of bronze patina from the flower-shaped bronze dishes, belong to Unified Silla period and 4 items from the Goryeo bronze bell were acquired and analyzed the lead isotope ratio. Based on the data of the lead isotope ratio from the galena of Korea, China and Japan, the provenance raw materials were estimated through the comparison of their lead isotope ratios. In the future, the Conservation Science Team of the National Museum of Korea will collect as much bronze patina as possible from the process of conservation treatment of metal objects, and analyze them in order to conduct the study of provenance with the type, period and the region of the objects.

• Korean Journal of Construction Engineering and Management
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• v.11 no.2
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• pp.106-115
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• 2010

Recently, as the size of construction projects are getting bigger and higher, more effective managing methods are required in management areas such as duration reduction, cost reduction and quality management. In the current construction industry, conjunction with IT(Information Technology) is being noticed as a solution to support these needs. Various IT solutions such as Bar Code, Personal digital assistant(PDA), global positioning system(GPS), radio frequency identification(RFID) are being developed. In this research, among the various IT solutions, the Real Time Locating System(RTLS) which is acknowledged as a technology with high applicational potential is analyzed. Based on this analysis, a locating system to apply in construction sites is developed and validated. The locating system is developed to prevent construction disasters through real-time management of workers and equipment, which enables effective application in the area of construction safety management. Moreover, applications of the locating system in many different areas like construction material realtime monitoring, construction automation, construction quality management, maintenance management are expected.

• Spatial Information Research
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• v.16 no.3
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• pp.279-290
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• 2008

Landslide, one of the serious natural disasters, has Incurred a large loss of human and material resources. Recently, many forecasting or alarm systems based on various kinds of measuring equipment have been developed to reduce the damage of landslide. However, only a few of these equipments are guaranteed to evaluate the safety of whole side of land slope with their accessibility to the slope. In this study, we performed some experiments to evaluate the applicability of a terrestrial LiDAR as a surveying tool to measure the displacement of a land slope surface far a slope collapsing protection system. In the experiments, we had applied a slope stability method to a land slope and then forced to this slope with a load increasing step by step. In each step, we measured the slope surface with both a total station and a terrestrial LiDAR simultaneously. As the result of Slope Fracturing analysis using all targets, the LiDAR system showed that three was 1cm RMSE on X-axis, irregularity errors on Y-axis and few errors on Z-axis compare with Total Station. As the result of Slope Fracturing analysis using continuous targets, the pattern of Slope Fracturing was different according to the location of continuous targets and we could detect a continuous change which couldn't be found using Total station. The accuracy of the LiDAR data was evaluated to be comparable to that of the total station data. We found that a LiDAR system was appropriate to measuring the behaviour of land slope. The LiDAR data can cover the whole surface of the land slope, whereas the total station data are available on a small number of targets. Moreover, we extracted more detail information about the behavior of land slope such as the volume and profile changes using the LiDAR data.

• Radiation Oncology Journal
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• v.15 no.2
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• pp.167-174
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• 1997

Purpose : The main Purpose of this study is to develop new payment rates for services of Radiation Oncology, considering costs of treating patients. Material and Methods : A survey of forty hospitals has been conducted in order to analyze the costs of treating patients. Before conducting the survey, we evaluated and reclassified the individual service items currently using as Payments units on the fee-for-service reimbursement system. This study embodies the analysis of replies received from the twenty four hospitals. The survey contains informations about the hospitals' costs of 1995 for the reclassified service items on Radiation Oncology. After we adjust the hospital costs by the operating rate of medical equipment, we compare the adjusted costs with the current Payment rates of individual services. Results : The current payment rates were 5.05-6.58 times lower than the adjusted costs in treatment planning services, 2.22 times lower in block making service, 1.57-2.86 times lower in external beam irradiation services, 3.82-5.01 times lower in intracavitary and interstitial irradiation and 1.12-2.55 times lower in total body irradiation. Conclusion : We could conclude that the current payment system on Radiation Oncology does not only reflect the costs of treating patients appropriately but also classify the service items correctly. For an example, when the appropriate costs and classification are applied to TBI, the payment rates of TBI should be increased five times more than current level.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.9
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• pp.1438-1443
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• 2001

The significance of the casting/forging process for reducing the production cost of large components is being noted in these days. This casting/forging process is a method of forging a workpiece preformed by casting into the final shape. In this study, the casting/forging process has been applied in manufacturing a large aluminum flange in order to reduce press capacity and material cost. Firstly, a hot compression test was performed with cast cylindrical billets in order to determine the optimum forging condition of the aluminum flange. The optimum range of forging temperature of Al 5083 was from 420$\^{C}$ to 450$\^{C}$. The suitable strain rate was 1.5 sec(sup)-1. The deformation amount of a preform of a preform in a forging process is a key role in the mechanical properties of casting/forging products. In order to find the change of mechanical properties according to effective stain of cast aluminum billets, a hot upsetting test were performed with rectangular blocks and then a uniaxial tensile test was performed with specimens cut from the upsetted billets. The tensile strength and the elongation of cast/upsetted aluminum billets were increased largely until the effective strain was 0.7. FE analysis was performed to determine the configurations of case preform and die for an aluminum flange. In the FE analysis, the forging load-limit was fixed 1500ton for low equipment cost. The cast preform was designed so that the effective stain around the neck of a flange exceeded 0.7. From the result of FE analysis, optimal configurations of the cast preform and the die were designed for a large flange. The filling and solidification analysis for a sound cast-preform was carried out with MAGMA soft. In the forging experiment for an aluminum flange, it was confirmed that the optimal configuration of the cast preform predicted by FE analysis was very useful. The cast/forged products using designed preform were made perfectly without any defects.

• The Journal of the Korea Contents Association
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• v.10 no.12
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• pp.236-242
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• 2010

The porcelain fused metal was made through the progressive fused process of porcelain on substructure of metal material. The substructure was made using novel SLM method. The objective of this study was to observe the color change of porcelain using spectrophotometer equipment according to porcelain fused step and production methods after conducting the process of casting and SLM method of the substructure. The color change by step was indicated that fused opaque porcelain groups(CN1, CC1, CT1, SC1, ST1) had color difference(${\Delta}E$=30) by comparison with fused body porcelain groups(CN2, CC2, CT2, SC2, ST2) and fused glazing porcelain groups(CN3, CC3, CT3, SC3, ST3) (p<0.05). and there was no color difference between the substrates(CN, CC, CT) made by the casting method and the substrates(SC, ST) made by the SLM method. so, the color change was expressed by fused change of porcelain, and this study showed that the color of porcelain fused metal made by the SLM method can be applied clinical trials.

• Korean Chemical Engineering Research
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• v.51 no.4
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• pp.438-442
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• 2013

The study of bioproduct production from inexpensive biomass such as marine biomass has recently attracted considerable attention. Because, marine biomass which compared to land biomass, it can be grown rapidly and is easily cultivated without the need for expensive equipment. In addition, the carbohydrate contents are similar or higher than land biomass such as woody biomass and can be easily converted to chemicals through proper chemical processes. In the production of various biochemicals from marine biomass, levulinic acid is a highly versatile chemical with numerous industrial uses and has the potential to become a commodity chemical. It can be used as a raw material for resins, plasticizers, textiles, animal feed, coatings and antifreeze. In this study, experiments were carried out to determine the optimum conditions of temperature, acid concentration and reaction time for production of levulinic acid from marine biomass, Gelidium amansii, using two-step treatment. In the first hydrolysis step, solid-state cellulose which was used to produce ethanol by fermentation and liquid-state galactose which used to produce bioproduct such as levulinic aicd were obtained through acid soaking. In the second hydrolysis step, the liquid-state galactose was converted into levulinic acid via a high-temperature reaction in a batch reactor. As a result, the overall production yield of Gelidium amansii to levulinic acid in the two-step acid hydrolysis was approximately 20.6% on the initial biomass basis.

• Analytical Science and Technology
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• v.22 no.6
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• pp.471-479
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• 2009

This study was performed to improve the analytical methods and re-establish the regulatory standard of PCBs-containing solid wastes for sufficient management in which has been concerned internationally. To do this, the sampling, pre-treatment and quantification methods which were used in USA and Japan were discussed. It was thought properly that new standard of PCBs-containing solid wastes was established through correlation with PCBs concentration of transformer oil. The surface wipe sampling was selected in the nonporous materials and cutting sampling in the porous materials. In the absence of transformer oils, electrical equipment is PCB-contaminated if it has PCBs at ${\geq}0.4{\mu}g/100cm^2$ as measured by a wipe test of a nonporous surface and if it has at 0.04 mg/L as measured by cutting test of a porous material. Also, new analytical methods for PCBs containing solid waste were proposed.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.2
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• pp.77-84
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• 2000

Aim to get operation factors, an In-vessel Composting of Wastewater Sludge was operated. The composting equipment is consisted of three chamber, 1st, 2nd and 3rd consequently. In the results, the temperature of fermentation had shown that 1st fermentation chamber(F/C) temperature was higher than that of 2nd and 3rd fermentation chamber. The temperature was steady in all steps during the sludge being composted, the ranges of each step were $50^{\circ}{\sim}59^{\circ}C$ of 1st F/C, $41^{\circ}{\sim}50^{\circ}C$ of 2nd F/C, and $32^{\circ}{\sim}37^{\circ}C$ of 3rd F/C. Organic material content of the end product was 28% and that of pH was 7.5. Properties of the compost which have been composted on optimized condition, were shown that is acceptable to use as a fertilizer. Even in the winter time, the composting system was working well without any trouble. According to result of investigation, the end-product of the system was satisfied with the standard for a fertilizer usage. HRT(hydraulic retention time) of entire process was appropriated to be 14 days(0.9 days at drying and 3.5, 4.4, 5.2 days at each step of fermentations, respectively).